OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 12*a(n-1) - 12*a(n-2) + 12*a(n-3) - 12*a(n-4) + a(n-5) for n>7.
Empirical g.f.: x*(8 - 7*x + 238*x^2 - 1448*x^3 + 238*x^4 - 5595*x^5 + 516*x^6) / ((1 - x)*(1 - 11*x + x^2 - 11*x^3 + x^4)). - Colin Barker, Jan 04 2019
EXAMPLE
Some solutions for n=4:
..7..1..2..9..4....0..7..9..3..4....0..1..2..3..4....6..1..2..3..4
..5.12..0..8..3....5..6.14..1..2...11.13..7.14..9...12.13..0..8..9
.17.18.19..6.14...17.11.18.13..8...16..5.18..6..8...10.17..5..7.14
.15.16.10.11.13...15.16.10.12.19...15.10.17.12.19...15.16.11.18.19
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 02 2015
STATUS
approved